Question

What is the difference between at least one head and at most one head in probability?

Answer 1

Difference between at least one head and at most one head in probability.

• At most one head means number of heads in probability is $0$or $1$.
• At least one head means the number of head is greater than or equal to $1$.

For example: If two coins are tossed together then the probability of getting at least one head , atmost one head is:

The possible outcomes are:

$\left\{HT,HH,TT,TH\right\}$

Now,$\left\{HT,HH,TH\right\}$

At least one head means the number of head is one or more than one that is $\left\{HT,TH,HH\right\}$

Atmost one head means the number of head is one or zero. That is $\left\{HT,TT,TH\right\}$

Thus, at most one head means number of heads in probability favourable outcomes is $0$or $1$. and at least one head means the number of head is greater than or equal to $1$.